rologie i - European Congress of Virology

5 th European Congress of VirologyWest Nile virus (WNV) is an emerging vector borne flavivirus causingencephalitis and other pathologies in humans and animals. It is transmittedby bites of infected mosquitoes, which acquire the infection from wildbirds acting as reservoir hosts. Humans and other mammals like horsesare dead end hosts, that is, although might develop clinical disease theydo not transmit the virus. In North America WNV was first observed in1999, while in Europe/Mediterranean region it re emerged in 1996. Sinceits first description in North America, WNV was associated with wild birdmortality events, a feature that was not evident in Europe/Mediterraneanregion, rising the question as to whether “Old World” bird species areless susceptible to die from WNV infection than “New World” ones. Inan attempt to answer this question we carried out a series of experimentsin which several Old world wild bird species (house sparrows, red leggedpartridges and common coots), were inoculated with different WNVstrains. As a result, the red legged partridge showed a high susceptibilityto WNV disease, in particular with certain Euro Mediterranean strains,while the house sparrow was found less susceptible. Virulence of differentWNV strains varied depending on bird species. Regarding host capacity,both red legged partridges and house sparrows reached viremias capableof transmitting the virus to mosquitoes. By opposite, though susceptibleto the infection, the common coot was unable to sustain a mosquito birdvirus cycle.(Funding: EU Grant HEALTH 2010.2.3.3 3 Project 261391 EuroWest-Nile).REF 287Mosquito, bird and human surveillance of Usutu virus in Germany in2011 and 2012Hanna JOEST 1,2 , Norbert BECKER 1,3 , Martin EIDEN 4 , UteZIEGLER 4 , Ludger ALLERING 2 , Marcus GRAEBERGERBERDING 2 , Stefan BOSCH 5 , Stephan GÜNTHER 2 , MartinGROSCHUP 4 , Jonas SCHMIDT CHANASIT 21 German Mosquito Control Association, Waldsee, GERMANY;2 Bernhard Nocht Institute for Tropical Medicine, Hamburg, GERMANY;3 Department of Zoology, Heidelberg, GERMANY; 4 Friedrich LoefflerInstitut, Riems, GERMANY; 5 Nature and Biodiversity ConservationUnion, Stuttgart, GERMANYUsutu virus (USUV) is a mosquito borne, single stranded RNA virus andbelongs to the Japanese encephalitis virus group within the family Flaviviridae.After the initial detection of USUV in German mosquitoes in August2010, the virus spread in 2011 and caused epizootics among wild and captivebirds in southwest Germany. Since June 2011, 407 dead birds werecollected and tested for the presence of USUV with real time RT PCRs,immunohistochemistry and isolation methods. USUV RNA was detectedby real time RT PCR in 157 birds representing 6 species. The virus wasisolated in cell culture from the heart of 14 Blackbirds. USUV specificantigen was demonstrated by immunohistochemistry in brain, heart, liverand lung of infected Blackbirds. In February 2012 USUV was detectedin hibernating Culex mosquitoes, demonstrating transovarial transmissionof USUV. As expected USUV was re detected in dead birds in June 2012USUV showing that the virus is still circulating in southwest Germany. Toinvestigate the medical importance of USUV, 4200 serum samples fromhealthy blood donors from south west Germany were collected in January2012 and analysed for the presence of USUV specific IgG antibodies. Oneserum samples originating from a healthy blood donor was tested positivein IFA and ELISA. Public health authorities and clinicians in Germanyshould be aware of the risk of USUV infection in humans and considerthis virus in cases of meningoencephalitis.REF 288Matrix M adjuvanted West Nile virus envelope protein vaccine leadsto protection against experimental West Nile virus infectionSofia E MAGNUSSON 1 , Karin H. KARLSSON 1 , Jenny M REIMER 1 ,Silke CORBACH SÖHLE 2 , Justin M RICHNER 3 , Sebastian ULBERT 4 ,Karin LÖVGREN BENGTSSON 1 , Michael S. DIAMOND 3 , LindaSTERTMAN 11 Isconova AB, Uppsala, SWEDEN; 2 University of Zürich, Institute ofLaboratory Animal Science, Zürich, SWITZERLAND; 3 Washington UniversitySchool of Medicine, St Louis, USA; 4 Fraunhofer Institute for CellTherapy and Immunology, Leipzig, GERMANYWest Nile virus (WNV) is an arthropod borne flavivirus and emergingpathogen. In elderly and immunosuppressed individuals infection can leadto neuroinvasive disease. No human WNV vaccine is available thoughveterinary vaccines exist. Recently there have been several WNV outbreaksin the US and Europe hence an increasing need of a human WNVvaccine exists. We have formulated recombinant WNV envelope (E) proteinwith particulate saponin based adjuvant Matrix M and studied antigenspecific immune responses in mice. Mice immunized with Matrix M formulatedWNV E protein developed higher IgG1 and IgG2a serum titers atantigen doses ranging from 0.5 to 10 g compared to mice immunized with3or10g of only antigen. Adjuvanted vaccine also significantly increasedWNV neutralizing antibody titers. This was accompanied by strongcellular recall responses as splenocytes from mice immunized with MatrixM formulated vaccine produced high levels of Th1 and Th2 cytokines andhad antigen specific CD4+ and CD8+ T cell proliferation. Addition ofMatrix M prolonged the immune response duration, as elevated humoraland cellular responses were maintained for 214 days. Importantly, micewere protected from WNV infection if vaccinated with Matrix M formulatedvaccine. In conclusion, addition of Matrix M to WNV E protein leadsto dose sparing and potent humoral and cellular immune responses thatare protective against WNV infection. This suggests that Matrix M adjuvantedWNV E protein is a promising human WNV vaccine candidate.This research was funded by EU FP7 project WiNgS grant no. 261426.REF 289Molecular characterisation of the African orthobunyavirus IleshavirusKarin PACHLER 1 , Daniel RUŽEK 2,3 , Norbert NOWOTNY 1,41 Institute of Virology, University of Veterinary Medicine, Vienna, AUS-TRIA; 2 Department of Virology, Veterinary Research Institute, Brno,CZECH REPUBLIC; 3 Institute of Parasitology, Biology Centre of theAcademy of Sciences of the Czech Republic, Ceské Budejovice, CZECHREPUBLIC; 4 Department of Microbiology and Immunology, College ofMedicine and Health Sciences, Sultan Qaboos University, Muscat, OMANIlesha virus (ILEV) is an arthropod borne virus belonging to the genusOrthobunyavirus, family Bunyaviridae. Orthobunyaviruses are lipid envelopedviruses with a genome of 3 single stranded RNA segments ofnegative polarity designated S (small), M (medium), and L (large). ILEVhas been isolated from humans in several African countries, mostly inrelation with febrile illness and erythema. However, ILEV has also beenreported in association with fatal meningo encephalitis and haemorrhagicfever (Morvan et al., 1994). Despite its known pathogenicity to man,only partial genetic information had been available. In the present study,the complete ILEV genome was determined including the viral noncodingends. Viral RNA was amplified by RT PCR with primers designedon basis of published sequences and degenerate orthobunyavirus primers,S200 Virologie, Vol 17, supplément 2, septembre 2013